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x^2 +6x=7 (x+3) ^2
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05 Dec 2017, 12:45
05 Dec 2017, 12:45
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Question Stats:
83% (00:39) correct
16% (01:16) wrong based on 89 sessions
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\(x^2 +6x=7\)
A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal
D. The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
\((x+3)^2\) |
\(16\) |
A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal
D. The relationship cannot be determined from the information given.
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: x^2 +6x=7 (x+3) ^2
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06 Dec 2017, 09:40
06 Dec 2017, 09:40
3
Carcass wrote:
APPROACH #1:
GIVEN: x² + 6x = 7
Quantity A: (x + 3)²
Quantity B: 16
Use FOIL to expand and simplify Quantity A:
Quantity A: x² + 6x + 9
Quantity B: 16
Notice the following:
Quantity A: x² + 6x + 9
Quantity B: 16
Replace x² + 6x with 7 to get:
Quantity A: 7 + 9
Quantity B: 16
Answer: C
Cheers,
Brent
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: x^2 +6x=7 (x+3) ^2
[#permalink]
06 Dec 2017, 09:43
06 Dec 2017, 09:43
3
Carcass wrote:
\(x^2 +6x=7\)
A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal
D. The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
\((x+3)^2\) |
\(16\) |
A. Quantity A is greater.
B. Quantity B is greater.
C. The two quantities are equal
D. The relationship cannot be determined from the information given.
Show: :: OA
OA in 24h
APPROACH #2:
GIVEN: x² + 6x = 7
Notice that the left side can be turned into a PERFECT SQUARE if we add 9 to both sides of the equation to get:
x² + 6x + 9 = 7 + 9
Factor left side and evaluate right side to get: (x + 3)² = 16
NOW ONTO THE QUESTION....
Quantity A: (x + 3)²
Quantity B: 16
Replace (x + 3)² with 16 to get:
Quantity A: 16
Quantity B: 16
Answer: C
Cheers,
Brent
